Dryer rack

ABSTRACT

A dryer rack for drying developed X-ray or other film including a pair of spaced side plates through which are journalled a plurality of film drying rollers and film guiding rollers. The film guiding rollers are positioned intermediate adjacent pairs of film driving rollers. A gear train is provided which is driven from a single source to rotate the film driving rollers at a first speed, and the film guiding rollers at a second speed, the second speed being approximately twice as great as the first speed. The dryer rack also includes a pair of opposed lower fan tiers which each comprise a plurality of propeller type fans which create great turbulence within the dryer rack for film drying purposes.

United States Patent Hope et al. July 22, 1975 DRYER RACK Primary Examiner-William F. ODea [76] Inventors: Henry F. Hope, 3192 Hunting Rd., Joyce Huntingdon Valley, Pa. 19006; Stephen F. Hope, 2548 Wyandotte Rd., Willow Grove, Pa. 19090 Filed: Apr. 4, 1974 Appl. No.: 458,391

References Cited UNITED STATES PATENTS 1/1968 Layne 226/189 X 10/1972 Hope et al. 354/339 X l/1974 Lee 226/189 X Attorney, Agent, or Firm-Weiser, Stapler & Spivak [57] ABSTRACT A dryer rack for drying developed X-ray or other film including a pair of spaced side plates through which are journalled a plurality of film drying rollers and film guiding rollers. The film guiding rollers are positioned intermediate adjacent pairs of film driving rollers. A gear train is provided which is driven from a single source to rotate the film driving rollers at a first speed, and the film guiding rollers at a second speed, the second speed being approximately twice as great as the first speed. The dryer rack also includes a pair of opposed lower fan tiers which each comprise a plurality of propeller type fans which create great turbulence within the dryer rack for film drying purposes.

9 Claims, 5 Drawing Figures PATENTED JUL 2 2 I975 SHEET FIG. I

FIG. 2

DRYER RACK BACKGROUND OF THE INVENTION The present invention relates generally to the field of photographic film developing equipment, and more particularly, is directed to a dryer rack for use with automatic X-ray and other film developing apparatus.

The present invention finds utility with small, selfcontained, automatic X-ray and other film processing machinery and the invention is equally applicable for use with all types of automatic photographic processers, such as development equipment suitable with X- ray, graphic arts, commercial film, etc. The device is useful in conjunction with presently available, selfcontained film processing units and greatly improves over all those prior art drying racks in efficiency of operation and in manufacturing and maintenance cost factors.

The prior art types of film processing equipment include various chemical containing tanks and rack assemblies mounted within the tanks to lead the film through the respective chemical containing tanks and then to automatically lead the film from the processing equipment to a film drying system for drying and delivery in a conventional manner. Prior to exiting the equipment, it is necessary to completely dry the film to prevent damage to the emulsion. In this regard, various types of blowers, baffles, guides and more or less complicated film directional apparatus have been employed to guide the film and to direct air currents upon the film surface for optimum overall drying. Due to the chemical treatment of the film within the various tanks, the film has a tendency to become quite limp when wet and thereby creates problems in automatically leading the film from roller to roller within the apparatus. All of the prior art types of dryer systems of which we are familiar have included fixed guide constructions of various configurations to automatically introduce the film to the nip of film drive rollers in a manner intended to prevent jamming of the equipment and to prevent damage to the film emulsion surface. Due to the fact that the chemicals within the various processing tanks act to render the film limp and the leading surface unstable or otherwise unresponsive to the action of rollers and guides, the prior art constructions have always proved deficient and unreliable in operation. Further, when considering films of extraordinary width, for example, film webs of up to fifty inches in width, the prior art types of guides have proved entirely ineffective and no satisfactory and reliable film guide for wide webs has as yet become available.

SUMMARY OF THE INVENTION The present invention relates generally to automatic Xray or other film processing equipment, and more particularly, is directed to a novel film dryer rack capable of automatically leading developed film through a dryer system in a reliable and rapid manner.

The dryer rack of the present invention receives the developed film from the processing tanks and automatically conducts the film through the dryer system without employing fixed guides, vanes or other permanent types of construction. The dryer system further includes opposed tiers of propeller fans which are designed to direct circulating air from the fans upon both sides of the film in a manner to fully utilize the drying capabilities of the air to assure drying the film in the least possible interval of time.

The dryer rack comprises a pair of right and left side carriers within which are journalled a plurality of pairs of upper and lower film driving rollers. The pairs of film driving rollers are spaced throughout the dryer rack in position to automatically convey the film through the rack. Intermediate the pairs of film guiding rollers are positioned cooperating upper and lower guide rollers which are spaced apart sufficiently to receive and guide the leading edge of the developed film. The film guide rollers rotate at approximately twice the speed of the film driving rollers and thereby act to propel and guide the leading film edge toward nip of the next down stream positioned pair of film driving rollers. By employing the high speed film guide rollers, the need for permanently affixed guides or other permanent construction can be completely eliminated to thereby positively prevent damage to the film emulsion or crinkling or jamming at the film drive rollers. By employing the high speed film guide rollers, any width of film can be accommodated, even up to 50 inches in width without any tendency on the part of the film to sag, curl, crinkle or jam.

It is therefore an object of the present invention to provide an improved film dryer rack of the type set forth.

It is another object of the present invention to provide a novel film dryer rack which incorporates a plurality of pairs of spaced film driving rollers and intermediate film guide rollers.

It is another object of the present invention to pro vide a novel film dryer rack wherein developed film is propelled through the rack by a plurality of pairs of film driving rollers and wherein the leading edge of the film is guided by film guide rollers which are positioned intermediate the pairs of film driving rollers.

It is another object of the present invention to provide a novel film dryer rack incorporating a plurality of pairs of film driving rollers, a plurality of film guide rollers intermediate the film drive rollers and a plurality of air circulating fans which direct air above and below the film surface, said fans creating air turbulence throughout the dryer rack for rapid film drying purposes.

It is another object of the present invention to provide a novel film dryer rack which includes a plurality of pairs of film driving rollers, a plurality of pairs of film guide rollers positioned intermediate adjacent pairs of film driving rollers and gear train means capable of rotating the film guide rollers at approximately twice the speed of the film driving rollers.

It is another object of the present invention to provide a novel film dryer rack that is rugged in construction, inexpensive in manufacture and trouble-free when In operation.

Other objects and a fuller understanding of the invention will be had by referring to the following description and claims of a preferred embodiment thereof, taken in conjunction with the accompanying drawings, wherein like reference characters refer to similar parts throughout the several views and in which:

. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the dryer rack of the present invention.

guide rollers positioned intermediate of a pair of adja cent film driving rollers.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of our invention selected for illustration in the drawings, and are not intended to define or limit the scope of the invention.

The invention will be described in particular with relation to automatic film developing equipment. However, it will be appreciated that the invention is not limited to such developing machines in that the same principles herein disclosed may be applied with equal facility to numerous other types of equipment having utility in moving a web of any thin material through a roller type of apparatus. 1

Referring now to the drawings, we show in FIG. 1 a dryer rack which comprises generally a forward section 12 and an exit section 14 and which is designed primarily for film drying and delivery purposes. The forward section 12 connects to an automatic X-ray or other film processing machine (not shown) in a conventional manner to automatically receive the film 66. The forward section 12 incorporates the power drive gear 16 which transmits power from the operating motor (not shown) to power the gear train 18 through a toothed drive belt 20. The exit section 14 includes a fully set forth. Each of the side plates 26, 28 is provided with a plurality of openings 30 which aid in circulating air throughout the system.

As best seen in FIG. 4, the dryer rack 10 comprises a plurality of tangentially contacting pairs of upper and lower film or other web driving rollers 32, 34 which are longitudinally spaced throughout the forward section 12 to guide the developed film toward the exit section 14 in a manner to drive the film without damage to the film emulsion. Interspaced between each adjacent pair of film driving rollers 32, 34 are positioned a pair of upper and lower film or other web guide rollers 36, 38 which are designed and which arepositioned to guide the film 66 to the respective nips 40 which are defined between the various pairs of upper and lower film driving rollers 32, 34. The film guide rollers 36, 38 function at higher rotative speeds than the upper and lower film driving rollers 32, 34 as hereinafter more fully set forth and serve to direct and guide the leading edge of the film 66 through the dryer rack 10 without the need for additional fixed, metallic guides or other conventional film directing apparatus. Still referring to FIG. 4, it will i be observed that upper and lowerfil m guide rollers are spaced apart to define an opening 76 therebetween to receive and guidethe leading edge of the film 66.

As best seenin FIGS. 2,. 3 and 4, each upper film driving roller 32 is provided with a shaft 42 which is rotatively journalled within the side plates 26, 28 in conventional manner such as by employing bushings (not illustrated). Similarly, the lower film driving rollers 34 are provided with shafts 44 which also extend through the side plates 26., 28 in a rotative manner. Each upper film guide roller 36 is provided with a shaft 46 and each lower film guide, roller, 38 is provided with a shaft 48 which shafts also extend through the side plates 26, 28 to rotatively carry the respective upper and lower film guide rollers 36, 38. Sufficient auxiliary guide rollers 50, 52 are provided forwardly and rearwardly of the film drive rollers 32, 34 in conventional manner to facilitate guiding the film 66 through the dryer rack 10. Referring now to FIG. 2, it is shown, that each lower film driving roller shaft 44 extends through the side plate 26. a sufficient distance topermita large drive gear 54 to be conventionally pinned or otherwise affixed thereto. Each large drive gear 54 is affixed to its associated shaft in a manner to rotate the lower film driving roller 34iupon the application of rotary forces on thelarge drive gear. The large drive gears 54 are preferably fabricated to the same diameter and with the same number of teeth, for example, thirty teeth. The gear teeth are contacted by the toothed drive belt 20 which acts to rotate all of the gears 54 in' unison as the power drive gear 16 is rot'atedfStill referring to FIG. 2, it is Shown that each upper film guide roller shaft 46 extends outwardly from the side plate 26 a sufficient dis tarice to permit asm'all drive gear '56 to be affixed in a conventional manner for rotation of the upper film guide rollers 36". The small and large drive gears 56, 54 are 'all positioned in the same vertical plane to rotate in unison upon function of the toothed drive belt 20. Preferably, each small drive gear 56' is formed with sixteen teeth torotate at a greater speed than the largedrive gears 54.

Thus, in calculating the speed of the film driving roller shafts 44 and the film guide roller shafts 46, assuming that the toothed drive belt 20 can be considered as a common driving gear having a known number of teeth N, the following formula may be utilized:

where R the revolutions per minute of the drive belt and n the number of teeth of the driven gear and r the number of revolutions per minute of the driven gear.

Inasmuch as the toothed drive belt 20 would be the equivalent of the driving gear and the belt 20 drives both the large drive gear 54 and the small drive gear 56, the product of the number of teeth times the revolutions-per'minute of each gear 54, 56 will equal a constant or the following formula can be derived:

n r (of large gear) r of small gear) Assuming the number of teeth in the large gear is 30 and the number of teeth in the small gear 56 is 16, the ratio of speeds of the small gear to the large gear will be proportional to the number of teeth of the large gear divided by the'number of teeth of the small gear. In the present situation, the ratio will be 30/16 or the speed of the small gear will be almost twice the speed of the large gear.

As best seen in FIG. 3, each upper film driving roller shaft 42 extends outwardly from the left side plate 28 and carries an upper driven gear 58, preferably having thirty teeth. Similarly, each lower film driving roller shaft 54 terminates outwardly beyond the left side plate 28 and carries a cooperating lower driven gear 60, preferably having 16 teeth. Thus, when the large drive gear 54 having 30 teeth is rotated by the belt 20 (FIG. 2) the shaft 44 is rotated to in turn rotate the lower drive gear 60 which is positioned at the opposite side plate 28 (FIG. 3). The lower drive gear 60 is fabricated with 16 teeth which mesh with the teeth of the upper driven gear 58, which is fabricated with 30 teeth. The interaction of the gears 60, 68 causes simultaneous rotation of the cooperating upper and lower film driving rollers 32, 34 at the same rotative speed as governed by the speed of the large drive gear 54. It will be noted in FIG. 4 that the pairs of upper and lower rollers 32, 34 are maintained in tangential contact to drive the film 66 at the nips 40 which are respectively formed therebetween.

As seen in FIG. 2, each small drive gear 56 is in mesh with the toothed drive belt 20 and is turned thereby at a rate of speed considerably greater than the large gears 54. Rotation of each small drive gear 56 rotates the upper film guide roller shaft 46 which in turn rotates the upper roller guide shaft gear 62. The upper roller guide shaft gear 62 meshes with the lower roller guide shaft gear 64 to cause simultaneous rotation of lower film driving roller shaft 48. By constructing the gears 56, 62, 64 to the same diameter with the same number of teeth, for example, 16 teeth, both of the upper and lower film guide rollers 36, 38 will be rotated at the same speed and at a speed which is considerably greater than the speed of rotation of the upper and lower film driving rollers 32, 34, for example, in the range of from one and one-half to two times as great.

Referring now to FIG. 5, the operation of the upper and lower film guide rollers 36, 38 will be described. As illustrated, a pair of upper and lower film guide rollers 36, 38 is positioned intermediate adjacent pairs of upper and lower film driving rollers 32, 34 and 32, 34'. Preferably, the film guide rollers 36, 38 are positioned closer to the downstream rollers 32, 34 to guide the film 66 in a downstream direction as the film is driven through the film dryer rack in the direction of the arrow 68.

It will be remembered that the film 66 is quite wet and limp after travelling through the film developing chemical tanks (not shown) and accordingly, the leading edge 70 of the film 66 has a tendency to bend or droop as illustrated after leaving the nip 40 between the upstream pair of film drive rollers 32, 34. Because of this tendency, the lower film guide roller 38 is rotated in the direction of the arrow 72 and is positioned intermediate the pairs of film driving rollers in a location to receive and direct the leading film edge 70 toward the downstream pair of film driving rollers 32', 34, in a path indicated by the dotted lines 74. As hereinbefore set forth, the film guide rollers 36, 38 turn at almost twice the rotative speed as the film driving rollers 32, 34, 32', 34 and this higher rotative speed together with the strategic location of the guide rollers 36, 38 serve to propel the film to the nip 40 of the downstream pair of film drive rollers 32', 34. It will be noted that the upper and lower film guide rollers 36, 38 are vertically spaced apart a distance to provide an open guide area 76 to receive the leading edge of the film 66 as it bends out of a straight path alignment between the respective film drive roller nips 40, 40'. The open guide area 76 preferably is designed to provide a vertical clearance between the rollers 36, 38 that is many times greater than the thickness of the film web 66 to provide a relatively high space to receive the leading edge 70. The upper and lower film guide rollers 36, 38 are spaced above and below the straight line path of travel between the respective film drive roller nips 40, 40' to thus guide the leading film edge 70 either upwardly or downwardly as necessary to enter the nip 40 of the downstream pair of film drive rollers 32', 34'. In this manner, the respective pairs of adjacent upper and lower film driving rollers 32, 34, 32, 34' can be spaced apart a greater distance to facilitate greater circulation of air for faster film drying results. Additionally, the intermediate film drive rollers 36, 38 extend entirely across the rack depth defined between the side plates 26, 28 and so serve to guide any portion of the leading edge 70 of the film 66 which bends out of the optimum straight line path of film travel. Preferably, the film guide rollers 36, 38 are positioned closer to the downstream pair of film drive rollers 32', 34. We have found that best results are obtained when the distance between the pairs of rollers 36, 38 and 32, 34 is from one third to one half the distance between adjacent pairs of film drive rollers 32, 34. and 32, 34.

The dryer rack 10 further includes an exit section 14 which is equipped with opposed right and left fan sections 22, 24 which act to develop air turbulence on both sides 78, 80 of the film 66. Each fan section 22, 24 includes a frame 82 upon which are mounted a plurality of propeller type fans 84 of the small, fractional horse-power type. The fans 84 direct the fan forces inwardly upon the respective film surfaces 78, 80 and throughout the interior 86 of the dryer rack 10. As seen in FIG. 1, the dryer rack 10 is equipped with a cover 88 to maintain the effluent streams from the fans 84 within the dryer rack 10 for film drying purposes. The air streams .generated by the fans 84 circulate throughout the interior 86 of the dryer rack in a turbulent manner to increase the drying capabilities of the device.

The fast speed of the upper and lower film guide rollers 36, 38 serves another purpose in addition to guiding the film 66. By employing the phenomenon known as the Flettner effect, the air from the fans 84 which impinges directly upon the rollers 36, 38 is accelerated by the rotary motion of the rollers and is compressed against the surfaces of the film to thereby aid and speed the drying operation. The employment of the guide rollers intermediate the film driving rollers 32, 34, 32', 34 permits the dryer rack to be designed with a greater spacing between adjacent pairs of film drying rollers. This greater spacing exposes more film surface to the drying effects of the effluent air from the fans 84 to additionally aid in the drying operations.

Although we have described the present invention with reference to the particular embodiments herein set forth, it is understood that the present disclosure has been made only by way of example and that numerous changes in the details of construction may be resorted to without departing from the spirit and scope of the invention. Thus, the scope of the invention should not be limited by the foregoing specification, but rather only by the scope of the claims appended hereto.

We claim:

1. In a rack assembly having an upstream end and a downstream end for moving a web of material, the combination of A. a pair of side plates arranged in spaced relationship;

B. a plurality of longitudinally spaced pairs of upper and lower web driving rollers rotatively carried by the side plates,

1. said pairs of upper and lower web driving rollers being in substantially tangential contact to form a web driving nip therebetween, said pairs of web driving rollers being substantially equally spaced apart;

2. the pairs of upper and lower web driving rollers being rotated at a first rotative speed;

C. a plurality of pairs of upper and lower web guide rollers, each pair being positioned intermediate adjacent pairs of web driving rollers,

1. said upper and lower web guide rollers being spaced apart to define an open guide area of height greater than the thickness of the web,

2. said web traveling through the open guide area,

3. the pairs of web guide rollers being rotated at a second rotative speed.

2. The invention of claim 1 wherein the second rotative speed is greater than the first rotative speed.

3. The invention of claim 2 wherein the second rotative speed is almost double the first rotative speed.

4. ln a rack assembly having an upstream end and a downstream end for moving a web of material, the combination of A. a pair of side plates arranged in spaced relationship;

B. a plurality of longitudinally spaced pairs of upper and lower web driving rollers rotatively carried by the side plates,

1. said pairs of upper and lower web driving rollers being in tangential contact to form a web driving nip therebetween;

C. means to rotate the pairs of upper and lower web driving rollers at a first rotative speed; and

D. a pair of upper and lower web guide rollers positioned intermediate adjacent pairs of web driving rollers,

1. said upper and lower web guide rollers being spaced apart to define an open guide area of height greater than the thickness of the web,

2. said web traveling through the open guide area,

3. the pair of upper and lower web guide rollers being longitudinally offset from the centerline between adjacent pairs of web driving rollers.

5. The invention of claim 4 wherein the pair of web guide rollers are positioned closer to the downstream pair of web driving rollers.

6. The invention of claim 5 wherein the pair of web guide rollers are positioned from the downstream pair of web driving rollers a distance that is between one third to one half the distance between the adjacent pairs of web driving rollers.

7. The invention of claim 6 wherein the web guide rollers are rotated at a speed which is greater than the rotative speed of the web driving rollers.

8. The invention of claim 7 wherein the web guide rollers are rotated a speed which is from one and onehalf to two times as great as the rotative speed of the web driving rollers.

9. In a rack assembly having an upstream and a downstream end for moving a web of material, the combination of A. a pair of side plates arranged in spaced relationship;

B. a plurality of longitudinally spaced pairs of upper and lower web driving rollers rotatively carried by the side plates,

1. said pairs of upper and lower web driving rollers being in tangential contact to form a web driving nip therebetween;

C. means to rotate the pairs of upper and lower web driving rollers at a first rotative speed;

D. a pair of upper and lower web guide rollers positioned intermediate adjacent pairs of web driving rollers,

1. said upper and lower web guide rollers being spaced apart to define an open guide area of height greater than the thickness of the web,

2. said web traveling through the open guide area and E. fan means associated with the rack assembly to create air turbulence about the web driving rollers and web guide rollers. 

1. In a rack assembly having an upstream end and a downstream end for moving a web of material, the combination of A. a pair of side plates arranged in spaced relationship; B. a plurality of longitudinally spaced pairs of upper and lower web driving rollers rotatively carried by the side plates,
 1. said pairs of upper and lower web driving rollers being in substantially tangential contact to form a web driving nip therebetween, said pairs of web driving rollers being substantially equally spaced apart;
 2. the pairs of upper and lower web driving rollers being rotated at a first rotative speed; C. a plurality of pairs of upper and lower web guide rollers, each pair being positioned intermediate adjacent pairs of web driving rollers,
 1. said upper and lower web guide rollers being spaced apart to define an open guide area of height greater than the thickness of the web,
 2. said web traveling through the open guide area,
 3. the pairs of web guide rollers being rotated at a second rotative speed.
 2. said web traveling through the open guide area,
 2. the pairs of upper and lower web driving rollers being rotated at a first rotative speed; C. a plurality of pairs of upper and lower web guide rollers, each pair being positioned intermediate adjacent pairs of web driving rollers,
 2. The invention of claim 1 wherein the second rotative speed is greater than the first rotative speed.
 2. said web traveling through the open guide area and E. fan means associated with the rack assembly to create air turbulence about the web driving rollers and web guide rollers.
 2. said web traveling through the open guide area,
 3. the pairs of web guide rollers being rotated at a second rotative speed.
 3. the pair of upper and lower web guide rollers being longitudinally offset from the centerline between adjacent pairs of web driving rollers.
 3. The invention of claim 2 wherein the second rotative speed is almost double the first rotative speed.
 4. In a rack assembly having an upstream end and a downstream end for moving a web of material, the combination of A. a pair of side plates arranged in spaced relationship; B. a plurality of longitudinally spaced pairs of upper and lower web driving rollers rotatively carried by the side plates,
 5. The invention of claim 4 wherein the pair of web guide rollers are positioned closer to the downstream pair of web driving rollers.
 6. The invention of claim 5 wherein the pair of web guide rollers are positioned from the downstream pair of web driving rollers a distance that is between one third to one half the distance between the adjacent pairs of web driving rollers.
 7. The invention of claim 6 wherein the web guide rollers are rotated at a speed which is greater than the rotative speed of the web driving rollers.
 8. The invention of claim 7 wherein the web guide rollers are rotated a speed which is from one and one-half to two times as great as the rotative speed of the web driving rollers.
 9. In a rack assembly having an upstream and a downstream end for moving a web of material, the combination of A. a pair of side plates arranged in spaced relationship; B. a plurality of longitudinally spaced pairs of upper and lower web driving rollers rotatively carried by the side plates, 